Diamidodiphenylamin sulfonic acid and process of making same.



UNITED STATES PATENT OFFICE.

HUGO GELDERMANN, OF BERLIN, GERMANY, ASSIGNOR TO ACTIEN- GESELLSOHAFT FUR ANILIN FABRIKATION, OF BERLIN, GERMANY.

DIAMIDODIPHENYLAMIN SULFONIC ACID AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Application filed November 1'7, 1904. Serial No. 233,218. (Specimens) To all whom, it may concern.

amidodiphenylamin sulfonic acids, which are of very great value for dyeing purposes, by reducing the corresponding nitroamidodiphenylamin sulfonic acid obtained by the action of para-chlornitrobenzene sulfonic acid:

on a meta-diamin of the benzene series, such as meta-phenylenediamin or metatoluylenediamin. These bodies are, as I have stated, an excellent means for dyeing leather in so far as they permit of a thorough penetration of the leather if black tints are to be produced therewith. In doing so these substances are to be used in combination with an oxidizing agent.

In carrying out my process I proceed as follows, the parts being by weight:

Example: Add 32.3 parts of para-methylmeta amidopara-nitrodiphenylamin-orthosulfonic acid, obtained by the action of paranitrochlorbenzene-ortho-sulfonic acid on metatoluylenediamin, with five hundred parts of water and eighty parts of hydrochloric acid, (12 Baum,) heat to the boil, and pour in twenty-one parts of zinc powder. The solution being decolorized, render alkaline by the addition of forty-two parts of sodium carbonate, filter the mass and acidify by the addition of dilute hydrochloric acid, so that the reaction will be a weakly-acid one. The reduction product is then precipitated by stirring in solid salt, filtered ofi" and dried. The diamidosulfonic acid thus obtained is with difiiculty soluble in water, easily soluble in soda-lye and in dilute hydrochloric acid. The solution in soda-lye becomes blue by the action of the atmospheric oxygen.

If the meta-amido-para-nitrodiphenylaminortho-sulfonic acid, obtained by the action of para-nitrochlorbenzene-ortho-sulfonic acid on meta-phenylenediamin, is substituted for the para methyl meta amido para nitrodiphenylamin-orthosulfonic acid in the above example I obtain the meta-amido-par a-amidodiphenylamin ortho sulfonic acid, which shows practically the same properties as the diamidodiphenylamin sulfonic acid obtained according to the above example.

Of course many variations may be made as to the proportions of the ingredients and to the temperature used during the reduction without essentially changing the result of my invention. Also instead of hydrochloric acid I may use any suitable mineral or organic acidas, for instance, sulfuric acid, acetic acid, &c.or instead of zinc powder I may use iron powder.

Now what I claim is 1. The process of making new diamidodiphenylamin sulfonic acids from the corresponding dinitro compounds obtained by the action of para-nitro-chlorobenzene-ortho-sulfonic acid upon aromatic meta-diamins of the benzene series, which process consists in treating the nitro compounds with reducing agents in the presence of a weakly-acidulated solution.

2. The process of making a new diamidodiphenylamin sulfonic acid of the following constitution:

NH C H .SO H.NH.O,,H .NH

from the corresponding nitro compound obtained by the action of para-nitro-chlorobenzene-ortho-sulfonic acid upon metatoluylenediamin, which process consists in treating at the boil the starting product with zinc powderlin the presence of a dilute hydrochloric aclc.

3. The new diamidodiphcnylamin-sulfonic acids, obtained by the reduction of the corresponding nitro compounds, these being obtained by the action of para-nitro-chlorbenzene-ortho-sulfonic acid upon meta-diamins of the benzene series, these new acids being with difficulty soluble in water, easily soluble in soda-lye and in dilute hydrochloric acid, the solution of which in soda-lye becomes blue by the action of the atmospheric oxygen and the aqueous solution of which shows blue precipitate on the addition of iron sesduichlorid or potassium bichromate.

4:. The new para-methyl-meta-amido-paranitro-diphenylamin-orthosulfonic acid, obtained by the reduction of the corresponding nitro compound as above set forth, being with difficulty soluble in Water, easily soluble in In Witness whereof I have hereunto signed my name, this 3d day of November, 19%, in I the presence 01' two subscribing Witnesses.

HUGO GELDERMANN.

\Vitn esses H ENRY HASPER, VVOLDEMAR HAUPT. 

